however ping would say nothing in that situation (e.g. my firewall may block not ping, but anything to port 3306 - actually it doesn't). Other mysql tools have no problem to connect.

It may be a wine issue or something that changed whil 3.1 /3.2 of heidisql was developed. It's hard to track down. The main window after the "connect" dialog just does not appear. nothing in taskbar visible from wine/heidisql. If you hit Ctrl-C a small (wine/heidsql) popup shows up saying that Ctrl-C was hit.

I did this, because the heidisql, on my xp, was not connecting to the database, on my Linux server. (I suspected that Fedora 9's mysql had a bug.)

On the surface, everything seemed to work fine, except, after a while, I noticed that heidi was taking a very-long time uploading data to my database.

After more than 5 hours, I stopped the process and started looking for a faster way.

I theorize that, since the server/database is located on the same Linux computer, as my Heidi, and Heidisql.exe is a windows program, then translations, from windows format to Linux format, might be slowing things down.